The HTTP::Response class encapsulates HTTP style responses. A response consists of a response line, some headers, and a content body. Note that the LWP library uses HTTP style responses even for non-HTTP protocol schemes. Instances of this class are usually created and returned by the request() method of an LWP::UserAgent object.

HTTP::Response is a subclass of HTTP::Message and therefore inherits its methods. The following additional methods are available:

Constructs a new HTTP::Response object describing a response with response code $code and optional message $msg. The optional $header argument should be a reference to an HTTP::Headers object or a plain array reference of key/value pairs. The optional $content argument should be a string of bytes. The meanings of these arguments are described below.

This is used to get/set the code attribute. The code is a 3 digit number that encode the overall outcome of an HTTP response. The HTTP::Status module provide constants that provide mnemonic names for the code attribute.

This is used to get/set the request attribute. The request attribute is a reference to the request that caused this response. It does not have to be the same request passed to the $ua->request() method, because there might have been redirects and authorization retries in between.

This is used to get/set the previous attribute. The previous attribute is used to link together chains of responses. You get chains of responses if the first response is redirect or unauthorized. The value is undef if this is the first response in a chain.

Note that the method $r->redirects is provided as a more convenient way to access the response chain.

Returns the base URI for this response. The return value will be a reference to a URI object.

The base URI is obtained from one the following sources (in priority order):

Embedded in the document content, for instance <BASE HREF="..."> in HTML documents.

A "Content-Base:" or a "Content-Location:" header in the response.

For backwards compatibility with older HTTP implementations we will also look for the "Base:" header.

The URI used to request this response. This might not be the original URI that was passed to $ua->request() method, because we might have received some redirect responses first.

If none of these sources provide an absolute URI, undef is returned.

When the LWP protocol modules produce the HTTP::Response object, then any base URI embedded in the document (step 1) will already have initialized the "Content-Base:" header. This means that this method only performs the last 2 steps (the content is not always available either).

Returns a filename for this response. Note that doing sanity checks on the returned filename (eg. removing characters that cannot be used on the target filesystem where the filename would be used, and laundering it for security purposes) are the caller's responsibility; the only related thing done by this method is that it makes a simple attempt to return a plain filename with no preceding path segments.

The filename is obtained from one the following sources (in priority order):

Calculates the "current age" of the response as specified by RFC 2616 section 13.2.3. The age of a response is the time since it was sent by the origin server. The returned value is a number representing the age in seconds.

Calculates the "freshness lifetime" of the response as specified by RFC 2616 section 13.2.4. The "freshness lifetime" is the length of time between the generation of a response and its expiration time. The returned value is the number of seconds until expiry.

If the response does not contain an "Expires" or a "Cache-Control" header, then this function will apply some simple heuristic based on the "Last-Modified" header to determine a suitable lifetime. The following options might be passed to control the heuristics:

Returns TRUE if the response is fresh, based on the values of freshness_lifetime() and current_age(). If the response is no longer fresh, then it has to be re-fetched or re-validated by the origin server.

Options might be passed to control expiry heuristics, see the description of freshness_lifetime().